Cost-effectiveness analysis of the addition of bevacizumab to first-line chemotherapy in metastatic colorectal cancer.

Abstract

3623 Background: The addition of bevacizumab (Bev) to either an irinotecan or oxaliplatin- based regimen in the systemic management of metastatic colorectal cancer is associated with a significant improvement in overall survival, but at the expense of a very high acquisition cost. We evaluated the cost-effectiveness of this combination using an era-to-era, population-based analysis. Methods: All patients with newly diagnosed metastatic colorectal cancer in 2003/04 (pre-Bev era) and 2006 (Bev era) referred to the British Columbia Cancer Agency were identified. Cost data are presented in the Table. An incremental cost-effectiveness analysis was constructed based on a Markov model that tracked major clinical and treatment events in the natural history of the disease. Probabilistic and one-way sensitivity analyses varying the median overall survival and median cost of treatment per patient were conducted to test the robustness of the model. Results: 943 patients were included: 611 from 2003/04 (pre-Bev era) and 332 from 2006 (Bev era). Median overall survival improved from 15.6 months in the pre-Bev era to 19.5 months in the Bev era (p=0.03). The weighted average cost of treatment per patient was $34,972 and $38,764 in the pre-Bev and Bev eras, respectively. In the Bev era, the cost of treatment resulted in an incremental cost-effectiveness ratio of $15,617/LYG, which translates into $62,468/QALY gained. Probabilistic sensitivity analyses produced an interquartile range of $38,900-$85,800/QALY, suggesting that the model is sensitive to the cost of systemic therapy. Conclusions: Even though Bev incurs in a high acquisition cost, it has also improved the cost-effectiveness of systemic therapy during the era in which it has been used. Expense Source Average cost per patient Pre-Bev (n=611) Bev (n=332) Diagnosis and staging StatsCan POHEM modeling $2115.38 $2115.38 Day surgery Ontario Case Costing Initiative $ 1,046.01 $ 1,136.00 Inpatient Ontario Case Costing Initiative $ 11,115.13 $ 14,718.00 Systemic Therapy BCCA provincial pharmacy database $ 20,672.62 $ 24,464.53 Radiation therapy BCCA radiation oncology database $ 3,843.40 $ 3,843.40 Author Disclosure Employment or Leadership Position Consultant or Advisory Role Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration Roche, sanofi-aventis Roche, sanofi-aventis